Door component comprising a controllable damping device

ABSTRACT

A door component has a controllable damping device containing a magnetorheological fluid as a working fluid. Two connection units can move relative to one another. One of the two connection units can be connected to a support structure and the other of the two connection units can be connected to a moveable door unit of a vehicle in order to damp a movement of the door unit between a closed position and an open position under control of a control device. The damping device has an electrically adjustable magnetorheological damping valve which is current-less in its adjusted state. A damping property of the damping device is continuously adjusted as needed via an electrical adjustment of the damping valve.

The present invention relates to a door component having a controllabledamper device, in particular for a motor vehicle. Here, the doorcomponent comprises two connector units which are movable relative toone another, the movement of which relative to one another can be atleast braked by means of at least one controllable damper device. Here,one of the two connector units is connectable or connected to asupporting structure, and the other of the two connector units isconnectable or connected to a pivotable door device, and in particular avehicle door.

In the prior art, a wide variety of door components has become knownwith which targeted damping of the door movement and in particular alsotargeted fixing of the door in predetermined angular positions ispossible. Normally, for this purpose, use is made of mechanical systemswhich are inexpensive and which allow the door of a motor vehicle to besecured in two or three angular positions. In this way, the user canmove the door into one of the angular positions that appears suitableowing to the present space situation, and can exit the automobile.

A disadvantage of said known mechanical systems is however that the dooris fixed only in a certain number of defined angular positions. If thereis presently less or even more space available, it may be the case thatthere is no suitable position.

Active systems have also become known in which the door can basically bebraked or fixed in any desired positions. A disadvantage of systemsactuated for example by means of a spindle is that these require arelatively long time for the opening or closing of the doors. Systemshave also become known which have for example a magnetorheologicalbrake, and in the case of which an electrical coil generates a magneticfield in order to achieve the desired damping action. A disadvantage ofsuch systems is that electrical energy is always required during theimparting of the damping action, which may entail considerable energyconsumption for example during a relatively long stoppage in a parkingspace, for example, with a door open.

A system has also become known in which the magnetic field required forthe damping action is generated by means of a permanent magnet. Aconsiderable advantage of this system consists in that the energyconsumption is low. It is however a disadvantage that, for example inthe event of an accident and a failure of the electrical systems, thedoor can be moved only with very high force, because a high dampingaction is generated by means of the permanent magnet. This may be aproblem specifically if elderly persons or children are seated in theautomobile and they can open the door only with difficulty, or possiblycannot open the door at all.

It is therefore the object of the present invention to provide a doorcomponent and a method, with which an at least partially improved doorcomponent, in particular for a motor vehicle, can be provided.

Said object is achieved by means of a door component having the featuresof claim 1. The subclaims relate to preferred refinements of theinvention. Preferred features, refinements and embodiments will also bediscussed in the general description and in the description of theexemplary embodiments.

A door component according to the invention has at least onecontrollable damper device and comprises two connector units which aremovable relative to one another, wherein one of the two connector unitsis connectable to a supporting structure, and the other of the twoconnector units is connectable to a movable door device, in particularof a (motor) vehicle, in order to dampen, in controlled fashion by meansof a control device, a movement (in particular pivoting movement) of thedoor device at least partially between a closed position and an openposition. Here a relative movement of the connector units which aremoveable with respect to one another can in particular be damped incontrolled fashion. The damper device contains in particular amagnetorheological fluid as working fluid. The damper device comprisesat least one electrically settable magnetorheological damping valvewhich maintains its set state when electrically deenergized, in orderfor a damping characteristic of the damper device to be permanently setas required by means of an electrical adjustment of the damping valve.

The door component according to the invention has numerous advantages. Aconsiderable advantage of the door component according to the inventionconsists in that a state of the magnetorheological dampening valve andthus also a state of the damper device can be set electricly. Aparticular advantage consists in that the damping valve maintains itsset state even when it is switched into an electrically deenergizedstate. In the context of the present invention, the expression“electrically deenergized” is to be understood to mean a state in whichthe damping valve and possibly also the damper device is largely orsubstantially or entirely electrically deenergized. A—very low—currentdemand may however continue to exist for the purposes of maintaining thecontrol function and possibly for the recording of sensor data.Therefore, in the context of the present invention, “electricallydeenergized” means that, on average, only an extremely small fraction ofthe normal current demand of the damping valve is required.Consequently, an electrically deenergized state is to be understood tomean a state of the damping valve in which the damping valve itselfrequires less than one percent and in particular less than one tenth ofa percent or less than 0.1 tenths of a percent of the current demandwhen it is electrically adjusted. The damping valve particularlypreferably maintains its set state when fully electrically deenergized.

In all embodiments, the door component may serve for damping a pivotingmovement of the movable door device, and in particular door, between theclosed position and an arbitrary open position. For example, the doorcomponent with the damper device may dampen the movable door device in acontrolled manner over the entire possible range of motion and inparticular pivoting range. It is however also possible for damping of apivoting movement to be realized only in certain angular ranges or atcertain angular points.

It is particularly preferable for the door device to be designed as adoor and to be pivotably accommodated on the supporting structure. Insuch embodiments, the door device can be referred to as a door. It isfor example also possible, on a vehicle, for a rear hatch, a rear lid orfor example an engine hood as a door device to be damped in targetedfashion during the opening and/or closing movement. Although theexpression “door” will generally be used below, the expression may alsobe replaced throughout by the expression “door device” or by “hatch” or“lid”.

It is also possible to use a sliding door as a movable door device. Itis then possible for targeted damping of the movement to be performedover a part of the opening or closing travel or over the entire slidingtravel or at defined points.

Here, the expression “damping” is to be understood to mean damping of amovement, which may also be referred to as braking. This means that thedamper device may also be referred to as a brake device. The damping ofthe movement may lead to fixing of the connector units that are movablerelative to one another, and thus of the movable door device, such thatthe door device is fixed in a particular position/angular position andcan be moved from there only by means of a particularly high force,which exceeds the maximum force of the damper device.

It is preferably possible for the movement of the connector unitsrelative to one another to be blocked in controlled fashion by means ofthe damper device.

The fact that the damper device comprises at least onemagnetorheological damping valve yields considerable advantages, becausethe magnetorheological damping valve can change its state in anextremely short period of time. Furthermore, it is possible incontactless fashion, and without a mechanical drive, for a magneticfield to be generated which influences the magnetorheological dampingvalve and thus adjusts the damper characteristic of the damper device.

In all embodiments, the door component may for example be designed as,or comprise, a driver's door or front passenger door or other vehicledoor. In the context of the present invention, a “door” of a doorcomponent is however also to be understood to mean a pivotable hatch orhood such as a front or rear lid of the vehicle such as a rear hatch oran engine hood.

The damping valve preferably comprises a flow channel (or multiple flowchannels) through which a magnetorheological liquid can flow, whereinthe flow channel can be subjected to a variable magnetic field. In thisway, the flow resistance of the flow channel and thus a damping actionof the damper device can be influenced by means of the magnetic field inthe flow channel. A more intense damping action is obtained in thepresence of an intense magnetic field than in the presence of a weakmagnetic field.

In preferred refinements, the magnetic field is permanently generated,or can be generated, by means of a magnet device composed at leastpartially of magnetically hard material. The magnet device preferablyacts (without external control influences) as a permanent magnet whichpermanently maintains its magnetic characteristics. The magnetization ofthe magnet device can be permanently changed by means of at least onemagnetic pulse of at least one electrical coil. In this way, themagnetically hard material (in the context of its materialcharacteristics) can be arbitrarily and in particular permanentlymagnetized. A magnetic pulse of an electrical coil of very shortduration is sufficient for the magnetization. Here, the magnetic pulseis preferably shorter than 1 second and in particular shorter than 50 msand shorter than 10 ms, and may even be considerably shorter. Themagnetically hard material of the magnet device reacts practicallyimmediately to a concentrated magnetic pulse, and changes itsmagnetization in particular permanently in a manner dependent on themagnitude and the duration of the pulse. In any case, the magnet devicemaintains the magnetic characteristics set by means of the pulse for atime period which is longer than the time duration of the pulse. Inparticular, the magnet device maintains the magnetic characteristics setby means of the pulse for a time period which is several times longerthan the pulse. The ratio is preferably greater the 2, greater than 10and in particular greater than 1000. If it is sought to reverse themagnetization of the magnet device, this may be realized by means of amagnetic alternating field with decreasing amplitude generated by meansof the electrical coil, or by means of a targeted counter-pulse. In thisway, the magnetically hard material can be demagnetized again, and cansubsequently be arbitrarily magnetized again by means of a targetedmagnetic pulse.

Through the use of a magnet device which is composed at least partiallyof a magnetically hard material, it is thus possible for a particularmagnetic field, which provides the desired damping action of the damperdevice, to be permanently maintained even without a supply of electricalcurrent.

This means for example that, during a stoppage in a parking space and inthe case of a door device or door being open for a relatively longperiod of time, a corresponding magnetic pulse can be generated. Thedesired damping is subsequently provided permanently without a furthersupply of electrical current. The door device (door) may even be fixedin the present angular position. After the transfer into the closedposition, the magnetization can be “deleted” by means of a correspondingmagnetic alternating field, such that no or only a very slight magneticfield acts on the damping valve of the damper device. The magnetizationof the magnet device after a closing process has taken place ispreferably always set to a minimum or very low value. This has theconsiderable advantage that, in the event of an accident, the (vehicle)door continues to exhibit free movement, and can be easily opened evenby children or elderly persons.

In all embodiments, it is preferable for at least one sensor device tobe assigned for detecting a measure for an (angular) position of themoveable door device. In this way, position-dependent and in particularangle-dependent or angle-optimized control is possible. It is preferablefor the sensor device to comprise at least one wheel or in particularfriction wheel, by means of which a measure for a relative movement ofthe two connector units with respect to one another can be detected.Here, it is in particular the case that the (friction) wheel lies on thepiston rod and is set in rotation as a result of the longitudinalmovement of the piston rod during the relative movement of the twoconnector units with respect to one another. The wheel or friction wheelis preferably connected to a rotary encoder. An advantage here is that arotational travel measurement is less expensive than a linear travelmeasurement. The same sensor/magnet ring/encoder can be utilized overseveral rotations.

Assuming a relatively high resolution, a linear travel measurement canbe implemented less expensively. Other linear measurement systems orsensor devices, which are for example not based on magnetic encoders,are also conceivable. An absolute travel measurement system may alsooffer advantages. An absolute travel measurement system is rotationallyrelatively difficult to construct, because it requires a large wheeldiameter, because in general only one rotation is admissible. It is alsoconceivable for two wheels (of different size) to be used. The absoluteposition can be determined from the two individual positions.

An expedient embodiment and reliable implementation are made possible byan incremental travel measurement system, which is in particularsupplemented with additional position information. Index pulses atparticular positions may for example be advantageous. This may be asingle index for example shortly before the end of the stroke, or elseeven a sensor provided in the door device or door (for example doorclosed). An advantage here is that “miscounting” by the sensor device isno longer critical; the sensor device finds its place again at definedpositions. Miscounting would be possible for example in the event ofslippage, or if for example the supply fails when the door device ordoor is open (battery change).

In preferred refinements, the control device is configured and designedto set the damping valve to a low (or relatively low) damping action,which acts in an electrically deenergized state, in the closed positionof the door device. The control device is preferably configured anddesigned to set the damping valve to an intense (or relatively intense)damping action, which acts in an electrically deenergized state, whenthe door device or door is in an open position and after a predefinedtime period has elapsed. The relatively low damping action, which actsin an electrically deenergized state, in the closed position offersconsiderable safety advantages. The intense damping action, which actsin an electrically deenergized state, in an open position isadvantageous if the user holds the door device open for a long period oftime. Then, in the case of an active system, energy is continuouslyrequired in order to maintain the damping action. With the presentinvention, only a one-off magnetic pulse is required, which subsequentlyensures damping or fixing of the door for an arbitrarily long period.

This preferably means that the control device is configured and designedto set the damper device to a low (relatively low) actuation force,which acts in an electrically deenergized state, when the door device isin the closed state, that is to say in the closed position. Inparticular, the control device is configured and designed to set thedamper device to a high (relatively high) actuation force, which acts inan electrically deenergized state, when the door device is open andafter a predefined time period has elapsed. In particular, when the doordevice or door is closed, the damper device or the damping valve iselectrically deenergized and set to a low damping action. During amovement of the door device or door, a low damping action is generallyset in order to allow the user to freely open the door device or door.When the open door device or door remains in a particular state, arelatively high damping action is set by means of a magnetic pulse andthe remanence of the magnet device.

The control device is preferably configured and designed to set thedamping valve to a low damping action, which acts in an electricallydeenergized state, during the movement of the door device.

In all embodiments, it is preferable that the magnetic field acting inthe flow channel can be modulated by means of an electrical coil. Thismeans that, for example in the case of a door device open for arelatively long period of time, a permanently acting magnetic field canbe set by means of a magnetic pulse. If the door device is then forexample moved slowly into the closed position by the user, an oppositelyacting magnetic field is generated by means of an electrical coil, suchthat the actually acting magnetic field in the damping channel of thedamping valve is reduced, and thus the door device can be pivotedfreely.

Here, it is possible for the electrical coil for modulating the magneticfield to also be used for generating the magnetic pulse. It is howeveralso possible for at least two electrical coils to be used, of which oneis used for example for generating a magnetic pulse for the permanentmagnetization. The other electrical coil may then be used for examplefor modulating the permanent magnet.

It is alternatively or additionally possible for at least onemechanically adjustable hydraulic valve to be provided as a dampingvalve. For example, a motor-adjustable hydraulic valve may be provided,which can be transferred from an open position into a partially or fullyclosed position by means of an associated electric motor. It is alsopossible by means of a mechanically adjustable hydraulic valve of saidtype to maintain a low damping action in an electrically deenergizedstate, or to maintain a relatively intense damping action in anelectrically deenergized state. In this case, electrical current isrequired only in order to open the mechanically adjustable hydraulicvalve to a corresponding extent, or to close said mechanicallyadjustable hydraulic valve.

The invention is also directed to a method for dampening a movement of adoor device, in particular of a vehicle, having a damper device with asettable and controllable dampening action, wherein a movement of thedoor device and in particular a pivoting movement of the door isdampened in controlled fashion at least partially between a closedposition and an open position. Here, the magnetorheological dampingvalve of the damper device is electrically set as required, andpermanently maintains the set damping characteristics in an electricallydeenergized state.

The method according to the invention also has numerous advantages,because it permits reliable damping with little energy use in a simplemanner.

A measure for the position of the door device (and in particular anangular position of the door) is preferably detected, and in this casethe damper setting or the damper device is set to a low damping action,which acts in an electrically deenergized state, in the closed positionof the door device (door) and it is preferably the case that, in theopen position, the damper device is set to a high damping action, whichacts in an electrically deenergized state, at least if the door device(door) has not moved significantly for a predefined time period.

In all embodiments, it is possible for a pivoting movement of the dooror a movement of the door device to be damped in controlled fashion atleast partially between a closed position and an open position. Here, ameasure for a rate of change of the movement speed of the door device orfor a rate of change of the rotational speed of the door can bedetermined, and, in the event of a rate of change beyond a predeterminedthreshold value, a switch can be made from a presently set relativelylow damping action to a relatively high damping action.

Such a method has numerous advantages. Said method permits saferoperation of a door component. Here, the rate of change of therotational speed is to be understood to mean the mathematical derivationof the rotational speed, that is to say the acceleration or thedeceleration. This means that, in the event of an excessive change inthe rotational speed, the controller intervenes in the dampingcharacteristic of the damper device. Here, the mathematical magnitude ofthe rate of change is taken into consideration. The threshold values fordeceleration and acceleration may be equal, though preferably differ.

This makes it possible for a relatively high damping action to be setpractically immediately in the event of an intense deceleration of thedoor device (door), in order to as far as possible prevent or at leastreduce or minimize damage. For example, if a door of a motor vehicle ismoved in a closing direction as a result of a gust of wind or as aresult of some other action, and if for example a leg or a hand or someother object is situated in the path of the closing movement, then thedoor initially—without further sensors—strikes the object and isunexpectedly braked in the process. This means that, for example in thecase of a relatively high rotational speed of the door, an unexpectedchange in the rotational speed occurs. This means here that the rate ofchange of the rotational speed exceeds a predetermined threshold value.The invention now makes it possible, in the event of such a processbeing detected, for a relatively high (and in particular maximum)damping action to be set immediately in the event of such a processbeing identified, such that damage can altogether possibly be avoidedentirely, or at least considerably reduced.

For example, during the opening of the door, the door may strike withthe flat body panel against a for example blunt obstruction, whichimmediately reduces the rotational speed of the door. Since the bodypanels can generally deform resiliently elastically over a small range,it is thus possible, in the case of an immediate action, for damage topossibly be prevented entirely.

This means that the deceleration of the door device (door) is preferablydetermined and that a deceleration of the rotational speed beyond apredetermined threshold value, the damping is switched from a relativelylow value to a high damping action. For this purpose, it is the case inparticular that the speed or the rotational speed of the door ismonitored.

In all embodiments, during the closing process, it is for examplepossible in all cases for the door to be braked when a small angle isreached, in order to thereby achieve a smooth or soft closing action.Such a small angle is for example 15° or 10° or 5°. In the case ofsensor-based identification of obstructions, braking can becorrespondingly performed in advance.

In preferred refinements, the damping is preferably set to asubstantially maximum value or to the maximum value if the rate ofchange or deceleration exceeds the predetermined threshold value.

In particular if a magnetorheological damping valve of the damper deviceis used, it is thus possible to achieve a very fast reaction of thesystem. Magnetorheological damper devices can completely change theirsetting within a few milliseconds, such that a time period of only a fewmilliseconds elapses from a state of minimum damping to a state ofmaximum damping. This means that, during actual closing movements, thedoor device (door) can be fully braked within less than 5 mm and inparticular less than 2 mm and preferably less than 1 mm and, inadvantageous embodiments, in approximately 0.6 mm. In the case of suchrapid braking processes, it is possible in many cases to avoidconsiderable damage, even if the user jams for example implements orobjects such as computers, or a body part such as a finger, a hand orother limbs, in the door device.

The damping action is preferably increased when the door device (door)approaches at least one predetermined position (angular position). Thismay for example be a predetermined open position. The damping action ispreferably increased when the door device (door) approaches the closedposition. For example, at a particular angular value of 15° , 10° or 5°,the damping may be intensified to such an extent that continuous andgradual braking is realized.

The damping action is preferably increased such that the movementspeed/rotational speed of the door device/door during a closing movementis reduced to a predefined closing speed. The closing speed is inparticular predefined such that smooth closing is performed, withpreferably little generation of noise.

In all embodiments, it is preferable for at least one learning functionto be integrated, with which closing speeds during closing processes areevaluated. In this way, the predefined closing speed is preferablyadapted if it is found that, during preceding closing processes, thedoor device/door was no longer moving sufficiently quickly for a closingprocess. The closing speed is set such that a speed that is justsufficient leads to reliable closing.

In preferred refinements, the damping action is preferably increasedwhen the door device/door approaches a maximum open position.

In all embodiments, the damping action is preferably increased only ifthe rotational speed exceeds a predefined rotational speed. In this way,it is for example possible to prevent the damping action being increasedduring the closing process despite the user guiding the door device/doorby hand.

In all embodiments, it is possible for at least one sensor to beassigned which identifies when the user touches the door device/door.

The increase of the damping action is preferably performed only if therotational speed exceeds a predefined rotational speed. In this way, itis also possible for unnecessary actions to be avoided, for example inthe event of measurement errors, noise or at extremely low speeds, suchas are caused for example as a result of oscillations of the door. Forexample, at a speed of 0.01 degrees/s or a speed of 0.1 cm/s at the doorhandle, there is generally no need for braking of the door to takeplace.

In all embodiments, the damping action is preferably increased if anobstruction is identified in the movement path of the door device/doorand a collision of the door device or door with the obstruction is inparticular immediately impending. Corresponding smooth braking until theobstruction is reached is preferable. For the automatic identificationof obstructions, use is preferably made of known sensors. In particular,ultrasound-based sensors, radar-based sensors and/or optical or acousticsensors are used.

The damper device is advantageously controlled such that the movementspeed profile or rotational speed profile of the door device/door issuch that quiet closing of the door is achieved and/or that a certainopening angle is reached without abrupt changes in speed. The control isperformed in particular such that the desired functions (desired openingangle, stoppage before an obstruction, standstill at an end stop) arerealized as desired. In combination with the fast switching ofmagnetorheological damping valves, it can thus be achieved that thespeed of the door device/door for example during the closing process isas low as possible already shortly before the closing. The damper devicethus requires less residual energy.

In further preferred embodiments, the door component comprises at leastone sensor device, or is assigned at least one sensor device, fordetecting a measure for a position/angular position of the moveable dooror the pivotable door. The control device is configured and designed todetermine a characteristic value for a change in speed of the movementspeed/rotational speed of the door device/door using sensor data of thesensor device, and to switch the damper device from a relatively lowdamping action to a relatively high damping action in the event of arate of change beyond a prior threshold value.

In this embodiment, and also in all other embodiments, the damper devicemay also be referred to as a brake device or as an immobilizing device.

The damper device is preferably designed as a magnetorheological damperdevice, and the damping action can in particular be set by means of avariable magnetic field. A magnetorheological damper device hasconsiderable advantages, because it permits extremely fast switching ofthe damping action from low to intense values and vice versa. The timeduration for switching from the relatively low damping action to therelatively high damping action is preferably less than 50 ms. Inparticular, a switch from a minimum damping action to a maximum dampingaction and vice versa can be achieved in less than 20 ms and preferablyin less than 10 ms and particularly preferably in less than 5 ms. Bymeans of such an extremely rapid system, it is possible to react to alldemands flexibly and in real time.

The damping is particularly preferably set to a substantially maximumvalue if the rate of change exceeds the predetermined threshold value.

The damping can be deactivated or set to a low value if the rotationalspeed has been reduced to 0. Here, a speed of 0 is also to be understoodto mean an extremely low residual speed which arises for example as aresult of oscillations, such that minimal speeds in one and the otherdirection of rotation arise constantly and in alternation.

The damper device preferably comprises at least one controllable flowchannel which is filled with a magnetorheological liquid, wherein theflow channel can be subjected to a variable magnetic field, such thatthe flow resistance of the flow channel and thus a damping action of thedamper device can be set to a more intense value by means of arelatively intense magnetic field in the flow channel and to arelatively weak value by means of a relatively weak magnetic field.

In a further embodiment, the door component comprises comprises acontrollable damper device which comprises a magnetorheological fluid asworking fluid. The (magnetorheological) damper device comprises a pistonunit and a cylinder unit surrounding the piston unit. The piston unitdivides a cylinder volume of the cylinder unit into two chambers. Here,the piston unit is equipped with a first one-way valve. The two chambersare connected to one another, by means of an external return channelwhich is equipped with at least one controllable magnetorheologicaldamping valve, so as to form a one-way circuit such that themagnetorheological fluid flows in the same flow direction (through thepiston unit) during the retraction and deployment of the piston unit.This means that the same flow direction exists through the firstthrottle valve or damping valve.

Such a door component has numerous advantages. Said construction permitsan embodiment in which only low forces preload the door in one or theother direction. At the same time, if required, by means of a fastadjustment of the magnetic field, a maximum damping force can be set ifrequired in order to prevent or reduce damage to trapped body parts.

A compensation volume is preferably provided on a low-pressure side ofthe damping valve. A compensation volume of said type serves inparticular for compensating the volume of a retracting piston rod.However, it is also possible for the piston unit to have one continuouspiston rod or two piston rods which are at both ends led out of thecylinder unit to the outside. If, for example, a continuous piston rodis used, the volume does not change as a result of the relative movementof the two connection units with respect to one another, and there istherefore no need for a compensation device or a compensation volume tobe provided for the volume of the piston rod. In such cases, too,however, compensation volumes may be advantageous in order, for example,to provide compensation in the presence of fluctuating temperatures(temperature compensation). Such a compensation volume may be referredto as temperature compensation volume.

By contrast, if use is not made of a continuous piston rod, then as thepiston rod plunges into the cylinder unit, the available volume isdecreased in size, such that the damping fluid that was previouslypresent there is displaced. If the compensation volume is arranged onthe low-pressure side of the damping valve, then a considerably lowerrestoring force is generated by the preloaded compensation volume. Inthis way, a movement in both pivoting directions is easier than if thecompensation volume were arranged on the high-pressure side of thedamping valve.

It is preferably also the case in this embodiment that the damping valvehas at least one flow channel through which a magnetorheological liquidcan flow, wherein the flow channel can be subjected to a variablemagnetic field, such that the flow resistance of the flow channel andthus a damping action of the damper device can be influenced by means ofthe magnetic field in the flow channel.

It is preferable for a first chamber of the two chambers to be connectedto the damping valve and for the damping valve to be connected in termsof flow to the second chamber by means of a second one-way valve. Here,the connection in terms of flow may be realized in each case indirectlyor directly. The second one-way valve preferably permits only a flowinto the second chamber. The first one-way valve permits only a flowfrom the second chamber through the piston into the first chamber.

In all embodiments, it is preferable for a compensation chamber with apreloaded compensation volume to be provided, wherein the compensationvolume is connected to the damping valve and to the second chamber. Thecompensation chamber may also be arranged in the flow path between thedamping valve and the second chamber.

In a further embodiment, the door component has at least onecontrollable damper device, which contains a magnetorheological fluid asworking fluid, and comprises two connector units which are movablerelative to one another, wherein one of the two connector units isconnectable to a supporting structure and the other of the two connectorunits is connectable to a movable door device, and in particular apivotable door, in particular of a vehicle, in order to dampen, incontrolled fashion by means of a control device, a movement of the doordevice or pivoting movement of the door at least partially between aclosed position and also a maximum open position, for example. Here, themagnetorheological damper device comprises a piston unit and a cylinderunit that surrounds the piston unit. The piston unit divides a cylindervolume into two chambers. Here, the piston unit has a first piston rod,which extends through the first chamber, and a second piston rod, whichextends through the second chamber.

Said door component also has numerous advantages and permits anembodiment in which the door can be moved practically without pressurein both directions.

It is preferable for both piston rods to be led in each case out of thecylinder volume and/or the cylinder unit to the outside. It is howeveralso possible for one of the piston rods to be of telescopic form, andto be fastened at one side to the piston and fixedly connected at theother side to the cylinder unit. The telescopic parts of the telescopicpiston rod are in particular sealed off with respect to one another. Insuch an embodiment, there is likewise no need for volume compensationfor the plunging of the piston rod. Temperature compensation ispreferably provided.

The damper device is preferably equipped with a controllable dampingvalve with a flow channel through which a magnetorheological liquid canflow. The flow channel can be subjected to a variable magnetic field,such that the flow resistance of the flow channel and thus a dampingaction of the damper device can be influenced by means of the magneticfield in the flow channel.

It is preferable for the damper device to comprise at least onecompensation device with a compensation volume, in particular forexample for compensating temperature fluctuations.

The compensation device preferably comprises a compressible compensationvolume. A compensation volume of said type may be formed by asponge-like structure, a rubber bladder or a closed-off and flexible airvessel.

It is preferable for at least one of the two piston rods to serve as anelectrical connector unit. It is then possible for at least oneconnector cable to be guided on the piston rod. It is also possible forconnector cables to be guided on or in both piston rods. The connectorcables or the connector cable may be guided in or on the piston rod. Itis possible for the required electrical current to be supplied via acable, and for signals to be transmitted in a manner modulated thereon.

It is preferable for at least one of the two piston rods to be received,outside the cylinder unit, in displaceable fashion in a tube equippedwith at least one slot. It is then preferable for the connector cable tobe guided out in the slot. The tube part is preferably a constituentpart of, or fixedly connected to, one of the connector units.

In all embodiments, it is preferable for the damper device to compriseat least one measuring device, wherein in particular, a part of themeasuring device is fastened to the piston rod. In the case of such ameasuring device, a measure for a pivoting movement of the door isdetected by means of a linear movement of the damper device. Since thereis a unique assignment between angle and linear position, it is possiblefor the pivoting position of the door to be inferred from the absoluteposition of the piston rod relative to the cylinder unit.Correspondingly, a rotational speed of the door can be inferred from thesignals of the measuring device. Also, a slowing of the acceleration ofthe door pivoting can be inferred from the signals of the measuringdevice. As a sensor, use may be made in particular of a wheel orfriction wheel which bears for example against the piston rod and whichdetects a relative movement of the piston rod.

In all of the above-described embodiments, it is preferable for the doorcomponent to comprise the door. It is also possible for the doorcomponent to comprise the supporting structure.

The sensor device preferably detects a measure for a pivot angle of thedoor and/or a measure for the relative position of the connector unitswith respect to one another.

In all embodiments, it is preferable for at least one position sensor tobe assigned which detects a measure for a horizontal orientation or ameasure for a deviation from the horizontal orientation of the vehicle.Then, the control device can control the damping action of the damperdevice in a manner dependent on the deviation from the horizontalorientation. It is for example expedient for an open door to be dampeddifferently if the vehicle is standing on a steep slope and there is therisk of the door falling closed or, in the case of a differentorientation of the vehicle, falling open.

In all embodiments, it is also preferable for at least one load sensorto be assigned for detecting a load applied to the door. With a loadsensor of said type, it is for example possible to detect a bendingmoment applied to the door.

It is furthermore preferable for at least one near-field sensor to beassigned, or for the signals of a near-field sensor to be used, foridentifying obstructions in the surroundings.

In all embodiments, it is possible for a virtual raster to be generatedby means of the control device such that, during the opening or closingof the door, the user senses raster points at particular angular stepsof for example 5° or 10°, or other distance steps, as the user isopening or closing the door.

In all embodiments and refinements, it is preferable for an electricalcoil to be arranged within the cylinder unit. In particular, theelectrical coil is arranged in the piston of the piston unit, and isarranged there is a so-called lying electrical coil. This means that thecoil axis is oriented transversely with respect to the longitudinalextent of the cylinder unit or transversely with respect to a relativemovement of the piston. The coil axis is in particular also orientedtransversely with respect to the flow direction of themagnetorheological damping medium. In this way, a particularly effectiveworking action is realized. An electrical coil in the piston unit ispreferably used in the case of damper devices which have one piston rodor two piston rods or one continuous piston rod. In the case of a damperdevice with a one-way circuit, it is by contrast the case that thedamping valve is preferably arranged outside the piston and outside thedamper chambers.

In one embodiment, an MRF damper device comprises a separating pistonwhich is acted on by air/gas, and thus a preloaded piston rodcompensation volume. This gives rise to a very simple and inexpensiveconstruction. As a result of the preload, the piston rod isautomatically deployed with a force. Depending on the preload pressure(air pressure in the piston rod compensation volume) and the doorkinematics, the door thus opens automatically.

Whereas it is the case during the opening of the door that the dampingforce can be adapted by means of the preset electrical current, it ispossible only for a limited (reduced) damping force to be generated—in amanner dependent on the preload pressure in the piston rod compensationvolume—during the closing of the door.

The system or the position of the separating piston may also be“reversed”, that is to say the piston rod then automatically retracts.Depending on the preload pressure in the piston rod compensation volume,a limited (reduced) damping force can be generated during the openingprocess.

In one variant, an MRF damper device is used in which the piston rodcompensation volume and thus the preload volume are situated on thelow-pressure side both during the opening process and during the closingprocess (virtually free from forces in both directions). Thus, thepreload force (a few Newtons) or the automatic movement is minimal, andthe generation of the full damping force is possible in both movementdirections (pulling and pushing side, or opening and closing).

The door component also offers considerable advantages for example inthe event of an electrical failure (for example after an accident. Animportant point is also that the failsafe characteristics can beconfigured such that the door can be opened easily and with little forcein the event of an accident. Here, for opening, only the basic dampingshould be overcome.

In the case of conventional systems, this is a problem. If a low basicforce is generated in an electrically deenergized state, then a largeamount of electrical current is required for the high holding force(damping force). In the event of an accident, the door can thus beeasily opened. However, if the vehicle is stationary with a door openfor a relatively long period of time, for example on a gradient, then alarge amount of current is required for holding the door. If the vehiclestands overnight in this state, then the battery is empty in themorning. A continuous consumer, of which there are in some cases even 4(four doors), is not practicable. Many vehicles already now switch offthe engine and the consumers after a few minutes.

By contrast, if the high basic force is generated in an electricallydeenergized state (for example by means of a permanent magnet), then thedoor can no longer be opened in the event of an accident. In particularif children are seated on the rear seats or if persons are injured, thedoors must be able to be opened with minimal force.

One solution would be to use a permanent magnet to generate not the fulldamping force, which in turn may be critical in the case of children inthe event of an accident (movement still too difficult) or in the caseof an inclined parking position (holding force is not sufficient).

A further solution would be an electrical current store which reducesthe high holding force after the accident. A disadvantage is the highcost. A further disadvantage is that, even with this, it cannot beensured that this will still function correctly after an accident or canprovide the required current for long enough (it must also still detectthe opening).

The invention offers an optimum solution here.

A further advantage is that the door can be moved by the user into anydesired position with regard to the opening angle. This may be realizedby the user guiding the door in continuous fashion until the desiredfinal angle is reached or by way of a striking action by the user.

The detent function of the system then holds the door at thecorresponding opening angle. Here, it is of no importance whether thevehicle as a whole is standing on a horizontal or inclined plane. Theuser however has the possibility of subsequently opening or closing thedoor further proceeding from said detent function. One conceivableenhancement of the detent function comprises that the door can be movedaway from the rest position of the detent function more easily in anopening direction than in a closing direction (unilaterally actingactuator). This is the case both on a horizontal and on an inclinedplane. In general, for this purpose, it is necessary to identify the“demand” for an opening or closing process by the user.

It is possible:

-   -   If the door is pushed against, there is a resulting specific        load moment. Depending on magnitude, this causes a movement of        the door. This may be identified/measured by means of suitable        sensors (for example travel, speed, acceleration) at suitable        locations (at the actuator, at the center of rotation of the        door, at the door handle etc.). Here, if a particular threshold        value is exceeded, the opening or closing process is/may be        initiated.    -   If the vehicle is situated on an inclined plane, then increased        load moments/basic moments arise in the detent position owing to        the masses acting on the damping system. This is preferably        correspondingly taken into consideration, for example by means        of an increase of the threshold values for the triggering of an        opening or closing process. The adaptive adaptation of the        threshold values may be realized using the information regarding        the vehicle inclination, which can be easily detected by sensor        means.    -   A further possibility for identifying an opening or closing        process is the use of contact or distance sensors of any type on        the outer and inner shells of the door (capacitive, inductive,        optical sensors; seat detection sensor (is the user situated on        the seat or not)). It is thus possible, if a hand or an object        is approaching or in the event of contact with the hand or other        objects, to identify whether an opening or closing process        should be permitted.

Furthermore, the processing of the information may be performed innear-field detection systems.

All of the abovementioned items of information may also be used toidentify whether the user wishes to use the door as a disembarking aid.In this case, too, it is of crucial importance whether the vehicle issituated on a horizontal or inclined plane. This can be taken intoconsideration correspondingly to the abovementioned methods.

Smooth opening and closing of the door is preferably made possible.

The detent function can be utilized such that, if the door is pushedopen or pushed closed or guided in one of the two directions by theuser, a smooth movement to the desired door angle always occurs. Duringthe closing of the door, for example, the door would always comesmoothly to a standstill at a defined opening angle. During the closing,mechanical or electromechanical components then later perform the finalclosing and fixing of the door. This is likewise the case during theopening of the door; regardless of the momentum/the impulse/the initialspeed/the guiding force to which the door is subjected, smooth openingto the desired opening angle always occurs.

The desired opening angle may in this case be:

-   -   the maximum opening angle. Here, owing to the smooth opening        process that is ensured permanently under all circumstances,        aside from the comfort, it is also ensured that the maximum        torque acting at the maximum opening angle is limited such that        a plastic deformation or fundamental overloading of the AB        pillar can be avoided. This is the case both for load situations        in which the vehicle is situated on a horizontal plane and those        in which it is situated on an inclined plane.    -   any angle within the working range.

Said desired opening angle may vary on the basis of:

-   -   manual user definitions or    -   automated functional enhancements, as described for example in        the next bullet point.

Furthermore, wear can be minimized as a result of a smooth opening orclosing of the door, by minimization of load peaks or through avoidanceof wear-increasing working ranges.

It is possible to provide a virtual stop on the basis of obstructions inthe working range (possible maximum opening angle of the door):

By means of suitable sensor equipment or from information from thenear-field detection, it can be identified whether an obstruction issituated in the working range of the door. For the near-field detection,it is possible here to use for example camera systems (under the doorsill or top view) or similar systems; furthermore, it is for examplepossible to use distance sensors etc. A virtual stop can be implementedon the basis of said information. Here, the maximum permitted openingangle is calculated/defined on the basis of the abovementionedinformation from the location of the obstructing object. On the basis ofthe new maximum possible opening angle, the functions described above(in all preceding points) are implemented with a reduced opening angle.It is also conceivable here for a safety distance to be taken intoconsideration in addition to the maximum possible opening angle. It isfurthermore possible (but not imperative) that, after the safetydistance to the obstructive object is reached, a raster function withany characteristic/granularity may be stored, with which a finelyincremented approach into the immediate vicinity of the obstructiveobject is made possible.

It is also possible for a blocking function to be implemented whichintervenes if objects of any type approach the working range of the door(for example approaching cyclists) before said door is opened/intendedto be opened. The information may be generated on the basis of suitablesensor equipment or on the basis of information from the near-fielddetection. The system processes said information such that an opening ofthe door is prevented on the basis of the adaptive damping.

A further advantage of the implementation with MRF actuators is that onthe basis of the adaptivity, environmental influences of all types canbe reacted to:

-   -   Wear phenomena in the system (for example increased door        friction with increasing age, etc.).    -   The temperature dependency of the door friction can also be        compensated. It is thus possible for the temperature at the door        mounting points to be taken into consideration.    -   External influences can be compensated. The action of wind can        thus be compensated. It is for example also possible for a snow        load on the rear hatch to be compensated.    -   Loading (if multiple persons are seated in the vehicle, the        ventilation of air from the interior space no longer functions        as effectively).    -   Windows open or closed: in the case of open windows, the doors        can be closed more easily.    -   Vehicle ventilation system: owing to aging, this can become        blocked, whereby the closing of the doors becomes more        difficult.    -   Vehicle is situated on an inclined plane (increased forces owing        to the masses involved).    -   Wind    -   Disturbance variables in general, regardless of their nature.

On the basis of all of the influences mentioned above, the behavior ofthe system changes in relation to the basic state/with aging/withtime/on the basis of temporary circumstances (for example inclinedplane). Said influences can however at best be detected and taken intoconsideration.

The detection is performed by means of (intelligent) algorithms whichobserve the system behavior, in conjunction with suitable sensorequipment. The control strategies—also described in all points above—maybe adapted such that the system behavior as a whole always remainsconstant, or is always perceived as constant by the user.

The door ideally always closes smoothly and with a full sound. For thispurpose, the movement speed is correspondingly controlled. If forexample the door seals change (swell up . . . ), the automobile isdistorted (after an accident, or one wheel is standing on the sidewalk),or the hinge has increased friction shortly before the closed position,the required closing force changes (it becomes greater).

The possibility of the adaptive adaptation of the damping yields severalpossibilities for increasing the comfort or increasing the performance,etc.:

-   -   By means of suitable sensor equipment or on the basis of the        information from the near-field detection, or for example by        means of a sensor in the key with personal information or by        means of cameras situated in the vehicle, it is for example        possible to identify which driver is situated as the user at the        system. In this way, the characteristics of all of the        above-described functionalities can be adapted to the present        user (for example adaptive damping of the moment for identifying        the “demand” for an opening or closing process; for example        male/female distinction).    -   It is furthermore possible, on the basis of the adaptation of        system parameters of the control, to react adaptively to all        circumstances without the need to perform any mechanical        adaptations during operation or during manufacture    -   front doors/rear doors    -   different vehicle model

With a simple configuration of the system, it can be achieved that, forexample, both rear doors cannot be opened during travel, or else in astandstill state. This may also be performed dynamically in a mannerdependent on the users situated on the rear seat bench. This may beidentified by means of suitable sensor equipment or on the basis of theinformation from the near-field detection or for example by means of asensor in the key with personal information or by means of camerassituated in the vehicle.

In general, the opening of the doors can be prevented during travel, orpermitted only below certain vehicle speeds, or permitted only withincreased difficulty.

Alternatively, if the door is opened during travel, a suitable dampingmeasure can be initiated (for example blocking of the door againstswinging back after the braking process).

Antitheft protection: The above functions may also be used for antitheftprotection (undesired embarking and disembarking is no longer possible).A further advantage here: it is thus also not possible for any articlesto be stolen from the vehicle (only by breaking the windows).

In the event of unspecifiable obstructions being detected in the workingrange (for example light snow) from the general sensor equipment or frominformation from the near-field detection, the system should for exampleprovide an adapted opening of the door. In the case of suchuncertainties, it would for example be possible for the system toprovide a finely graduated raster function from the start of the openingprocess. Thus, by means of the automatically generated haptic feedback,the user is provided with the feedback that unassignable obstructions(which have only a limited damaging effect) are situated in the workingrange.

Furthermore, aside from a maximum opening angle based on obstructions inthe working range for the opening process of the door, it is likewisepossible for a maximum closing angle based on obstructions in theworking range for the closing process to be taken into consideration(virtual end stop during the closing movement). It is thus possible fornot only damage to articles on the vehicle (owing to obstructions suchas for example beverage crates) during the closing process but alsoinjuries to persons, for example trapping of fingers or hands, to beprevented. In general, however, painful/injurious trapping of forexample fingers/hands is assisted already by the comfort function of thesmooth closing. This is because said function already brings the door toa standstill in all situations with little residual energy (residualspeed) before the detent function.

Anti-trapping protection: Here, an algorithm or a control regime canabruptly apply a high electrical current to the actuator in the event ofan unusual speed reduction shortly before the closed door position, suchthat said door is in particular braked as quickly/intensely as possible.The fast reaction time of the actuator is highly expedient here. Amovement speed of 0.5 m/sec equates to 0.5 mm/ms, and thus, in the caseof a reaction time of 6 ms, the door component comes to a standstillwithin 3 mm.

Damage minimization: the sensor equipment identifies no obstruction, andit is intended to open the door in unhindered fashion. The travel sensormonitors the opening and identifies an atypical movement (for exampleintense braking owing to an undetected obstruction such as a low post inthe center of the door). The “MRF emergency stop” imparts a full brakingaction (as described above with reference to “anti-trapping protection”;a movement speed of 0.1 m/sec =0.1 mm/ms; in the case of 6 ms, it takes0.6 mm to come to a standstill) and, owing to the very fast reactiontime, thus reduces the damage (the body panel is possibly onlyelastically deformed as a result . . . ).

This is also important in the case of snow, bushes, branches, etc., thatis to say obstructions that are difficult to detect.

Various circumstances of environmental influences can be taken intoconsideration. For example, a situation may arise in which, when theuser is absent from the vehicle, a further vehicle parks adjacent to theuser's vehicle, which vehicle was not present when the user departed. Inthis case, it should be ensured that the general sensor equipment, orthe information from the near-field detection before the opening of thedoor, transmits the maximum opening angle to the SDS system in goodtime. If said value before the opening of the door is not adapted (forexample if the final value before the user departed the vehicle isused), then damage may occur in some form. For example, it will becomenecessary to find concepts which continuously update such information(even during “non-operation” of the vehicle). This may be realized forexample by means of reduced processing (for reduction of the energyrequirement) of the corresponding sensor equipment and/or algorithmsand/or near-field detection systems in the form of a stand-by function.It is in any case preferable that this is performed before the initialactuation of the door; the advance time is in this case dependent on theperformance of the algorithms/sensor equipment thatdetermine(s)/measure(s) the maximum opening angle. It is preferable forobstructions to be newly detected upon actuation of the door lock.

Sensors may be used inter alia on the exterior mirror, on the door sill,under the body panel, on the inside or on the outside. The sensors maybe attached vertically to the window frame.

With the use of remanence, two magnet devices may be used, of which thefirst magnetic field unit is a magnetic field unit with steel core, coiland flow channel. The second magnetic field unit is a remanence systemwith remanence material in the core and/or in the rest of the magneticcircuit. If a high damping force is required over a relatively longperiod of time, the remanence material is magnetized by means of acorresponding electrical current pulse (or electrical current pulseprofile). After the renewed application of an electrical current pulseor electrical current pulse profile, the magnetic field is reduced againor eliminated entirely. When the door is closed, no remanence field,therefore easy opening possible in the event of an accident.

In the case of a flow of for example 0 to 3 amperes, the magnetic fieldcan be generated as in a “normal” magnetic field unit. Increasingcurrent=greater magnetic field=greater damping force. All of thiscontinuously variable and very rapid (<10 ms).

Electrical current pulses or electrical current pulse profiles of forexample 5 to 6 amperes remagnetize the remanence material, whereby aresidual magnetic field remains. In this way, a (high) holding force canbe generated without a supply of electrical current.

In all embodiments, it is also possible for an active system to be used.

Here, the following problem arises. The automatic opening and closing ofthe doors, as is the case nowadays with luggage compartments, willbecome established. The use of the current luggage compartment closingmechanisms (spindle drives) in the driver's or front passenger's doorwill not be desired, because these are far too slow (the customer doesnot wish to wait several seconds before being able to embark) and arevery loud. Furthermore, in the event of an accident, the system cannotbe opened (very high forces required in the electrically deenergizedstate). If the spindle drive also then deforms, the door no longer opensat all. Furthermore, the door forces are very high in relation to theluggage compartment cover (100 Nm when the automobile is in an inclinedposition). In the case of the luggage compartment cover, a gas spring orthe gravitational force assists during the closing process.

In all embodiments, it is possible to use nitrogen or argon orlarge-molecule gases, which are less volatile, as actuator medium or ascompressible medium in for example the compensation volume.

Gas dampers from the prior art generally have the problem in vehiclesthat, owing to the temperatures, the forces change significantly (gasvolume; low temperatures—lower pressure; high temperatures—higherpressure). This yields differences in the characteristics. In the caseof the invention with a magnetorheological damper device, temperaturecompensation is preferably performed. In all embodiments, it istherefore preferably possible to compensate an (outside) temperature.For this purpose, it is for example possible for the electrical coil tobe additionally electrically energized, and thus for the damper deviceto be heated. It is however also possible for a separate heating device(only for low temperatures) to be installed, for example a heating wire,a heating sleeve around the damper device etc. The heating device may beactivated for example when the user enters the vicinity of the vehicle,that is to say at an early time (Keyless Go . . . ) or uses the door.The heating device may however also be programmed (e.g. mornings . . .).

Preferably, the door component comprises an electrical lock. A “softclose” facility is possible, wherein the door closes automatically inthe final millimeters. This is preferably actuated in the reversemanner, that is to say the door is released (and the lock opened). Thedoor is preferably then automatically opened, for example by virtue ofthe adaptive damper pushing the door open. The driver can thus open thedoor, in order to embark, using a smart device (mobile telephone, smartwatch . . . ) or a radio key. The driver does not need to touch the doorfor this purpose, which, aside from the increased comfort, also has theadvantage that the driver does not need to make his or her hands dirty,because the user indeed no longer has to touch the door in order to openit. It is also conceivable for the user to open the door by means ofgesture control (for example a foot movement at/under the door), whichis advantageous if the user has his or her hands full (for example aftershopping). Furthermore, the user can embark directly, in particular ifhe or she approaches the vehicle from behind (the rear).

It is possible for only one door (for example the driver's door or therear doors) to be equipped with the invention.

In current vehicles from the prior art, the door hinges are in somecases mounted (door kinematics) such that the door moves more easily inone direction than in the other. This can be compensated by means of thedoor component according to the invention.

It is now possible to use an active system with an MRF pump, in the caseof which an MRF valve is used as a pump.

The drive motor can be driven in both drive directions. Depending on thedirection of rotation of the motor, a cylinder connected thereto isretracted or deployed. To realize control of the cylinder speed, the MRFvalve can divert 0% to 100% of the volume flow via a bypass.

In all embodiments, it is possible in the context of the presentinvention for the relatively broad expression “door device” to berestricted to the more specific expression “door”, and for theexpressions to be correspondingly interchanged. Furthermore, in allembodiments, it is possible for the invention to be concretized as apivotable door or pivotable flap or a pivotable lid such as a rear lid.In this context, a movable door device comprises a pivotable door, andmay be restricted thereto or concretized as such, such that, throughoutthe entire description, the expression “movable” may be rendered moreprecisely as “pivotable”. Conversely, the expression “door” may bereplaced by “door device”, and the expression “pivotable” may bereplaced by “movable”.

It is also possible for an opening and/or closing movement of a top of acabriolet to be damped using the invention. In such embodiments, themovable top is to be regarded as a door device, and the entire structurewith the supporting structure and the top held thereon is to be regardedas a door component.

The invention is not restricted to use in automobiles, and may also beused in for example trucks/heavy goods vehicles; agricultural vehicles,other (motor) vehicles, autonomous vehicles, taxis, items of furniture,aircraft and military vehicles.

It is also possible for an opening and/or closing movement of a top of acabriolet, for example, to be damped using the invention. In suchembodiments, the movable top is to be regarded as a door device, and theentire structure with the supporting structure and the top held thereonis to be regarded as a door component. The applicant reserves the rightto direct a claim to a vehicle apparatus or other apparatus in which amovable device is held on a supporting structure so as to be movablebetween an open position and a closed position and in the case of whichthe movement can be damped by means of a magnetorheological damperdevice.

Further advantages and features of the present invention will emergefrom the description of the exemplary embodiments, which will bediscussed below with reference to the appended figures.

In the figures:

FIG. 1 shows a schematic plan view of a vehicle with a door componentaccording to the invention;

FIG. 2 shows a schematic exploded illustration of the door component asper FIG. 1;

FIG. 3 shows an enlarged cross section of the door component as per FIG.1;

FIG. 4 shows another embodiment of a door component according to theinvention;

FIG. 5 shows a further embodiment of a door component according to theinvention;

FIG. 6 shows a yet further embodiment of a door component according tothe invention; and

FIG. 7 shows a schematic cross section through a damping valve of a doorcomponent according to the invention.

FIG. 1 shows a schematic plan view of a motor vehicle 100 stopped at theedge of a road, in which motor-vehicle there are provided in this casetwo door devices 53 designed as doors, which are both open. The doorsare situated in each case approximately in an angular position 13. Thedoors 53 are each part of a door component 50, which in this casecomprises the doors 53. It is equally possible for a door 53 to beattached to the door component 50. The door component 50 comprises, inany case, connector units 51 and 52 for connection to the supportingstructure 101 of the vehicle 100 and to the door 53, for the purposes ofholding the door pivotably on the supporting structure 101. Here, thedoor may be composed of multiple units, which are in each case pivotableand which are articulatedly connected to one another. The door may beheld so as to be pivotable about one or two or more pivot axes. Hatchingis used to show a door 53 in the closed position 2, in which the door inthis case terminates flush with the vehicle.

FIG. 2 shows, in an enlarged illustration, an exploded illustration ofthe door component 50, wherein the door component 50 comprises a damperdevice 1 which has a damper which operates on a magnetorheologicalbasis.

The door component 50 in FIG. 2 has connector units 51 and 52 forconnection to the supporting structure 101 and to the door 53, in ordera defined and controlled pivoting of the door during the movement fromthe open position illustrated in FIG. 1 into the closed position 2 alsoindicated in FIG. 1.

The damper device 1 comprises a cylinder unit 31, in which the piston 38of the piston unit 30 divides the cylinder volume 32 into a firstchamber 33 and a second chamber 34 in a variable manner.

A compensation volume 36 of a compensation chamber serves for thecompensation of the piston rod 43 plunging into the cylinder unit 31.

FIG. 3 shows an enlarged cross-sectional illustration of a part of thedoor component 50 from FIG. 2.

On the assembled damper device 1 that is illustrated in section here, itis possible to see the piston unit 30 with the piston 38 in which themagnet device 9 with the electrical coil 10 is arranged. The piston 38divides the cylinder volume 32 of the cylinder unit 31 into a firstchamber 33 and a second chamber 34. The damping valve is arrangedoutside the piston unit 31. The magnet device 9 with the electrical coil10 is arranged on the damping valve.

Furthermore, in the cylinder unit 31, the compensation device with thecompensation chamber 37 and the compensation volume 36 is illustrated.The compensation chamber 37 is separated from the second chamber 34 by aseparating piston, which slides in a variable manner within the cylinderunit 31. It is also possible for the compensation chamber to be locatedon the other side, wherein sealing is then necessary with respect to thepiston rod extending through and with respect to the first chamber 33.The compensation chamber 37 is situated on the low-pressure side of theone-way circuit. Valves 47 and 48 for the filling of the first andsecond chambers 33, 34 and of the compensation chamber 37 are provided.The compensation chamber 37 is filled with a gaseous medium at a lowpressure, such that the plunging-in volume of the piston rod 43 can becompensated.

To the piston rod 43 there is attached a sensor device 12, by means ofwhich in this case an absolute position of the damper device 1 can bedetected. By interrogation of the sensor device, the position of the twoconnector units 51 and 52 with respect to one another can be detected,such that, by means of the sensor device, the angular position of thedoor 53 is also directly detected.

The connector cables for the electrical coil in the piston 38 and thesensor device 12 are in this case guided through the piston rod 43 tothe outside.

FIG. 4 shows a variant in which one continuous piston rod or 2 pistonrods 43, 44 are provided. The interior of the cylinder unit 31 isdivided further by the piston 38 into 2 chambers 33 and 34. Here, thetwo piston rods 43 and 44 are guided to the outside at the respectiveends, such that there is no need for a plunging-in of the volume of apiston rod to be compensated. To be able to compensate a change involume as a result of temperature differences, a compensation device 39is provided here, which is designed for example as a hollow rubber ringor the like, and which thus provides corresponding volume compensationby way of a volume expansion or decrease in volume as a result oftemperature differences. Such a compensation device may be arranged inthe chamber 33 or in the chamber 34.

Compensation devices in both chambers 33 and 34 are possible.

In all embodiments, the piston 38 is also designed as a damping valve 5,and has one or 2 or more flow channels 7 which connect the first chamber33 to the second chamber 34. The chambers 33 and 34 are filled with amagnetorheological fluid 6. The damping is in this case achieved byvirtue of a magnet device 9 or at least one magnet device 9, whichcomprises magnetically hard material and in this case also an electricalcoil, being arranged on the damping valve 5.

By means of a short electrical pulse at the coil 10, a magnetic pulse istriggered, which leads to a permanent magnetization of the magnet device9, such that, subsequently, the flow resistance through the flow channel7 increases in a manner corresponding to the intensity of the actingmagnetic field 8.

By means of corresponding remagnetization of the magnet devices 9, it isthus possible to set any desired damping of the door movement of thedoor 53. It is furthermore possible, in addition to a permanently actingmagnetic field, to use the coil 10 to dynamically model the magneticfield 8 of the magnet devices 9. By means of a magnetic field orientedin the same direction, the damping can be intensified, and by means of acorrespondingly oppositely oriented magnetic field, the damping can beattenuated or even reduced to zero.

In this exemplary embodiment, the connector cable 42 or the connectorcables 42 are guided to the outside through the piston rod 44. Thepiston rod 44 is displaceably received in a tube 46. Here, at the end ofthe piston rod 44, the connector cable 41 is guided out of the pistonrod and is guided to the outside through a slot 42 in the tube 46.

By way of example for all exemplary embodiments, a schematic controldevice 4, by means of which the damping valve 5, the damper device 1and/or the door component 50 as a whole can be controlled, is shown inFIG. 4. The control device 4 may also be part of the vehicle 100 or ofsome other apparatus.

FIG. 5 shows another variant in which 2 magnet devices 9 or at least 2electrical coils 10 and 11 are provided. The magnetic coils 10 and 11 ofthe magnet devices 9 are in turn arranged in the piston 38 of the pistonunit 30 within the cylinder unit 31. In this case, too, the pistonseparates 2 chambers 33 and 34 of the cylinder volume 32. First andsecond piston rods 43 and 44 can be provided on both sides or only onepiston rod is guided out on one side. In such a case, a compensationchamber 37 having a compensation volume 36 is again required.

Here, an electrical coil 10, 11 is used for generating a magnetic pulseand for the permanent magnetization of the magnet device 9. Therespective other electrical coil 11, 10 can be used for the modulationof the presently acting magnetic field.

FIG. 6 shows another schematically illustrated variant of a damperdevice 1 of a door component 50 with connector units 51 and 52. Thedamper device 1 has a magnetorheological fluid 6 as working fluid. Apiston unit 30 with a piston 38 separates a first chamber 33 from thesecond chamber 34. At least one flow channel 7 leads through the piston.The one-way valve 15 opens for the flow of the magnetorheological fluidfrom the second chamber 34 into the first chamber 33. From there, theworking fluid is conducted through the return channel 35 to the in thiscase external damping valve 5, which is assigned a magnet device 9 andan electrical coil 10, in order to set the desired damping. The dampingvalve 5 is in turn connected in terms of flow to the second chamber 34via a line 49 and a second one-way valve 16.

Both during the plunging of the piston rod 43 into the cylinder unit 31and during the deployment of the piston rod 43 out of the cylinder unit31, the working fluid 6 flows in the same direction along the indicatedarrows. Depending whether the piston rod is being plunged in or deployedout, magnetorheological fluid is fed to the compensation chamber 37 ormagnetorheological fluid is removed from the compensation chamber 37. Inthe compensation chamber 37, there is provided a compensation volume 36,which is filled with a gas.

One or more sensor devices 12 may be provided in order to detect arelative position of the two connector units 51 and 52 with respect toone another, in order to derive an angular position of the door 53therefrom. In all embodiments, it is however also possible for otherangle sensors to be provided, for example at the rotary joint, such thatan angular position is directly output.

In this case, too, an electrical coil 10 is used for the generation of amagnetic pulse and for the permanent magnetization of the magnet device9. The same or another electrical coil may be used for the modulation ofthe presently acting magnetic field.

FIG. 7 shows a schematic cross section through the cylinder unit 31 andthe piston 38 arranged therein. It is clearly possible to see the flowchannels 7 of the damping valve 5, which are in this case each dividedfurther into two sub-channels by means of a partition. Also shown is amagnetic field line of the magnetic field 8. The magnetic field passesapproximately perpendicularly through the flow channels 7 of the dampingvalve. The electrical coil 10 serves for the generation of a variablemagnetic field, and in particular also for outputting a magnetic pulsein order to magnetize the magnet device 9 as desired.

It is correspondingly also possible, as illustrated in section in FIG.7, for an external damping valve for the door component, for example, tobe designed as per FIG. 6. All of the parts shown are then preferablyimmovable relative to one another. The flow channels 7 of the dampingvalve 5 may each be divided into two sub-channels by means of apartition. In this case, too, the magnetic field again passesapproximately perpendicularly through the flow channels 7 of the dampingvalve 5. The electrical coil 10 serves for generating a variablemagnetic field and may in particular also be used for outputting amagnetic pulse in order to permanently magnetize the magnet device 9 asdesired.

LIST OF REFERENCE DESIGNATIONS

1 Damper

1 Damper device

2 Closed position

3 Open position

4 Control device

5 Damping valve

6 MRF

7 Flow channel

8 Magnetic field

9 Magnet device

10 Electrical coil

11 Electrical coil

12 Sensor device

13 Angular position

14 Predetermined angular position

15 First one-way valve

16 Second one-way valve

18 Magnetic pulse

19 Time period

20 Rate of change

21 Delay

22 Rotational speed

23 Limit value of 20

24 Relatively low damping

25 Relatively high damping

26 Maximum damping

27 Damping

28 Closing speed

29 Second compensation channel

30 Piston unit

31 Cylinder unit

32 Cylinder volume

33 First chamber

34 Second chamber

35 Return channel

36 Compensation volume

37 Compensation chamber

38 Piston

39 Compensation device

40 Electrical connector unit

41 Connection cable

42 Slot

43 First piston rod

44 Second piston rod

45 Diameter of 43

46 Tube

47 Valve

48 Valve

49 Line

50 Door component

51 Connector unit

52 Connector unit

53 Door

54 Angular position

60 Obstruction

100 Vehicle

101 Supporting structure

1-27. (canceled)
 28. A door component, comprising: a controllable damperdevice containing a magnetorheological fluid as working fluid and havingtwo connector units that are movable relative to one another, said twoconnector units including a first connector unit connectable to asupporting structure and a second connector unit connectable to amovable door device; said damper device being configured to dampen,under control by a control device, a movement of the door at leastpartially between a closed position and an open position; said damperdevice including at least one electrically settable magnetorheologicaldamping valve which maintains a set state thereof in an electricallydeenergized state, in order, through electrical setting of said dampingvalve, to permanently set a damping characteristic of said damper deviceas required.
 29. The door component according to claim 28, wherein saiddamping valve is formed with a flow channel configured to conduct amagnetorheological liquid therethrough, wherein said flow channel is tobe subjected to a variable magnetic field, to thereby influence a flowresistance of the flow channel, and thus to set a damping action of saiddamper device by way of the magnetic field in the flow channel.
 30. Thedoor component according to claim 29, which comprises a magnet deviceconfigured to permanently generate the magnetic field, said magnetdevice being composed at least partially of hard magnetic material, andat least one electrical coil disposed to permanently change amagnetization of said magnet device by way of at least one magneticpulse generated by said at least one electric coil.
 31. The doorcomponent according to claim 28, which comprises a sensor devicedisposed to detect a measure for an angular position of the movable doordevice, said sensor device being a friction wheel disposed to detect ameasure for a relative movement of said two connector units with respectto one another.
 32. The door component according to claim 28, wherein:the control device is configured to adjust said damping valve to arelatively low damping action, which acts in an electrically deenergizedstate, when the door is in the closed position; and the control deviceis configured to adjust said damping valve to a relatively intensedamping action, which acts in an electrically deenergized state, whenthe door device is in an open position and after a predefined timeperiod has elapsed; and the control device is configured to adjust saiddamping valve to the relatively low damping action, which acts in anelectrically deenergized state, during a movement of the door device.33. The door component according to claim 29, which comprises anelectrical coil configured to modulate the magnetic field acting in theflow channel.
 34. The door component according to claim 29, whichcomprises at least two electrical coils, including a first electricalcoil for outputting magnetic pulses for adjusting a permanentmagnetization of said magnet device, and a second electrical coil formodulating the magnetic field that acts in said flow channel.
 35. Thedoor component according to claim 28, wherein said damping valve of saiddamper device is a mechanically settable hydraulic valve.
 36. The doorcomponent according to claim 28, wherein: said damper device comprises apiston unit and a cylinder unit surrounding said piston unit, andwherein said piston unit divides a cylinder volume into two chambers;said piston unit is equipped with a first one-way valve and said twochambers are connected to one another by way of an external returnchannel that is equipped with at least one controllablemagnetorheological damping valve, forming a one-way circuit in which themagnetorheological fluid flows in one given flow direction through saidpiston unit during a retraction of said piston unit and during adeployment of said piston unit.
 37. The door component according toclaim 36, wherein said piston unit includes a continuous piston rodhaving two ends projecting outwardly out of said cylinder unit.
 38. Thedoor component according to claim 36, wherein said two chambers includea first chamber connected to said damping valve, and a second chamberconnected to said damping valve via a second one-way valve, and furthercomprising a compensation chamber having a preloaded compensation volumeconnected to said damping valve and to said second chamber.
 39. The doorcomponent according to claim 38, wherein said piston unit includes afirst piston rod that extends through a first of said two chambers, anda second piston rod that extends through a second of said two chambers,and said first and second piston rods are each led out of said cylindervolume and/or said cylinder unit to the outside.
 40. The door componentaccording to claim 39, wherein one of said piston rods is a telescopicrod having a first side fastened to a piston of said piston unit and asecond side fixedly connected to said cylinder unit.
 41. The doorcomponent according to claim 39, wherein one of said two piston rodsserves as an electrical connector unit, and wherein at least oneconnection cable is guided on said piston rod.
 42. The door componentaccording to claim 39, wherein at least one of said two piston rods isdisplaceably received, outside said cylinder unit, in a tube that isformed with at least one slot.
 43. The door component according to claim42, wherein said tube forms a part of one of said connector units. 44.The door component according to claim 36, wherein said damper devicecomprises at least one measuring device, and wherein a part of said atleast one measuring device is fastened to a piston rod of said pistonunit.
 45. A method of damping a movement of a door device, the methodcomprising: providing a damper device with a settable and controllabledamping action; damping a movement of the door device in a controlledprocess at least partially between a closed position and an openposition; and electrically adjusting a damping valve of the damperdevice as required, and permanently maintaining respectively set dampingcharacteristics in an electrically deenergized state of the dampingvalve.
 46. The method according to claim 45, which comprises: detectinga measure for an angular position of the door device; when the doordevice is in the closed position, setting the damper device to arelatively low damping action to act in an electrically deenergizedstate of the damping valve; and when the door device is in the openposition and the door device does not move significantly for apredefined time, setting the damper device to a relatively high dampingaction to act in the electrically deenergized state.